1. Field of the Invention
The present invention relates to a fine needle cytology aspiration device for removing tissue and body fluid samples from a patient.
2. Description of the Prior Art
In fine needle cytology aspiration it is necessary to draw body fluid and tissue samples for later analysis without allowing the samples to be contaminated with fluids or tissues from non-target locations as the needle is withdrawn. For this reason, fine needle cytology aspiration devices which allow the breaking of the vacuum in the device before the needle is withdrawn have been proposed in the prior art.
U.S. Pat. No. 4,967,762, issued to DeVries, shows a fine needle aspiration device which uses a rubber O-ring to seal vents which can be used to release the vacuum in the needle.
U.S. Pat. No. 4,543,094, issued to Barnwell, U.S. Pat. No. 5,104,381, issued to Gresl et al., U.S. Pat. No. 3,834,372, issued to Turney, U.S. Pat. No. 4,619,272, issued to Zambelli, and U.S. Pat. No. 3,774,604, issued to Danielsson, all show rotating valves for medical applications. All the devices shown in the above cited patents suffer from the drawback that they require two hands for their operation.
U.S. Pat. No. 5,127,904, issued to Loo et al., shows an infusion system having an injection port for administering medications.
U.S. Pat. No. 4,857,061, issued to Miller, shows a syringe having a one-way valve which a swinging flap. Miller does not show the sliding valve of the present invention.
U.S. Pat. No. 5,097,842, issued to Bonn, shows a sliding valve which only has two internal channels and does not provide for venting the system to the atmosphere.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.